JP2006019147A - Insulated cable and manufacturing method of insulated cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulated cable in which bridging impediment on the surface of a coating layer can be eliminated and surface fusion of the cables can be prevented and, further, a manufacturing method of an insulated cable in which an inert gas supply portion can be made unnecessary from the manufacturing device of the insulated cable. <P>SOLUTION: The insulated cable 10 is formed by forming a first coating layer 12 made of an insulating material around a conductor 11 and by forming a second coating layer 14 made of the insulating material around the first coating layer 12, and then, after irradiating electron beams, is formed by removing the second coating layer 14. The insulated cable 10 is so constructed that the heat deflection temperature of the insulating material constituting the second coating layer 14 is made lower than the heat deflection temperature of the coating layer material constituting the first coating layer 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insulated wire and a method for manufacturing an insulated wire, and more particularly to an insulated wire suitable for use in an environment where heat resistance is required, such as a vehicle wiring including an electric vehicle, and a method for producing the insulated wire.

  Insulated wires generally have a conductor disposed in the center and a coating layer of resin or the like formed around the conductor. Depending on the application, an insulated wire in which a braided or laterally wound outer conductor (also called a shield layer) is further provided around the covering layer covering the conductor is also used.

In recent years, with the advancement of automobile automatic control technology, electric vehicle technology, and the like, there is an increasing demand for insulated wires having high heat resistance for electric wiring of vehicles. By imparting high heat resistance to the insulated wire, the allowable current value of the wire can be increased, and the center conductor can be made smaller and the covering layer can be made thinner, so that the diameter of the wire itself can be reduced. As a result, it is possible to reduce the size and weight of internal devices such as automobiles.
As a means of improving the heat resistance of insulated wires, a technique is known in which a coating layer is formed of a resin such as polyethylene or polyvinyl chloride, and the resin inside the coating layer is crosslinked by irradiating the coating layer with an electron beam. Yes.

Patent document 1 is disclosing the method of performing electron beam irradiation to the coating film provided on the base material using the apparatus provided with the inert gas supply part in addition to the coating-film formation part and the radiation irradiation part. . In this method, an inert gas is supplied from an inert gas supply unit to a coating film forming unit and a radiation irradiating unit, and a coating film is formed by the coating film forming unit, and a coating film is crosslinked and cured by the radiation irradiation unit. Is carried out in an inert atmosphere.
JP 2000-343022 A

  By the way, it is known that when the electron beam irradiation is performed in the air atmosphere, oxygen in the air becomes a factor of inhibiting the crosslinking of the coating layer. If the crosslinking of the coating layer is inhibited, an uncrosslinked portion remains on the surface layer of the coating layer, and if the insulated wires are densely packed in a high temperature environment, the surfaces of the insulated wires may be fused.

In Patent Document 1, as a measure for inhibiting the crosslinking of the coating layer, coating film formation and electron beam irradiation are performed in an inert gas atmosphere. However, even with this method, oxygen may enter due to deterioration of the apparatus or the like. There is a risk that cross-linking inhibition occurs.
Also, the electron beam irradiation device is larger in equipment than other ultraviolet irradiation devices and the like, and as in Patent Document 1, an inert gas supply unit is provided in both the coating film forming unit and the electron beam irradiation unit. Then, the whole apparatus becomes further large and expensive.

  The objective of this invention is providing the manufacturing method of the insulated wire which can provide such an insulated wire cheaply, and the insulated wire which does not generate | occur | produce the surface fusion | melting of wires even if it puts in a high temperature environment.

  In order to achieve the above-described object, an insulated wire according to the present invention is formed by forming a first coating layer made of an insulating material on a conductor, forming a second coating layer around the first coating layer, After the irradiation, the second coating layer is removed.

  According to the insulated wire having the above configuration, the second coating layer is formed on the first coating layer, irradiated with the electron beam, and then the second coating layer is removed, whereby the first coating layer is removed from the atmosphere, that is, oxygen. It is possible to irradiate with an electron beam in a state of being isolated from the surface, and it is possible to improve the surface fusion of the insulated wire in a high temperature environment by eliminating cross-linking inhibition of the first coating layer.

In addition, the insulated wire according to the present invention forms an insulating layer on a central conductor, disposes an outer conductor around the insulating layer, forms a first covering layer made of an insulating material around the outer conductor, A second coating layer is formed around the first coating layer, and after the electron beam irradiation, the second coating layer is removed.
According to the insulated wire having the above-described configuration, even when the external conductor (shield layer) is provided, it is possible to improve the surface fusion of the insulated wire in a high temperature environment without obstructing the crosslinking of the first coating layer.

In the insulated wire according to the present invention, the second covering layer is preferably made of an insulating material.
By forming the second coating layer with an insulating material, the second coating layer can be formed by extrusion molding, and the formed second coating layer can be removed by breakage. It can be done easily.

In the insulated wire according to the present invention, the thermal deformation temperature of the insulating material of the second coating layer is preferably lower than the thermal deformation temperature of the insulating material of the first coating layer.
By setting the thermal deformation temperature of the insulating material constituting the first coating layer and the second coating layer as described above, the first coating layer does not melt when the second coating layer is formed. Can be easily removed.

In the insulated wire according to the present invention, the thickness of the second coating layer is preferably 1 mm or less.
By reducing the thickness of the second coating layer, the second coating layer can be easily removed from the first coating layer.

It is preferable that the insulated wire which concerns on this invention is provided with the groove | channel along the longitudinal direction in the surface of the 2nd coating layer.
The groove provided along the longitudinal direction makes it possible to easily break the second coating layer, and the second coating layer can be easily removed from the first coating layer.

In the insulated wire according to the present invention, the adhesion between the first coating layer and the second coating layer after irradiation with the electron beam is preferably smaller than the adhesion between the first coating layer after irradiation with the electron beam and the lower layer.
By setting the adhesive force as described above, only the second coating layer can be easily removed. Furthermore, when the second coating layer is removed, there is no possibility of reducing the adhesion between the first coating layer and the lower layer, and the influence on the workability and dielectric constant of the insulated wire can be avoided.

In the insulated wire according to the present invention, the insulating material constituting the first covering layer is preferably a polyester resin.
Since the polyester resin is excellent in heat resistance, using this polyester resin as an insulating material for the first coating layer is advantageous in securing high heat resistance of the insulated wire.

In the insulated wire according to the present invention, it is preferable that the force when the two insulated wires are pressed at 0.7 kgf for 1 hour in an atmosphere of 150 ° C. to separate the insulated wires is 500 gf or less.
By adopting such a configuration, surface fusion between the insulated wires at high temperatures can be suppressed, and when the insulated wires are separated from each other, there is no appearance abnormality such as breakage or peeling marks of the insulated portions.

The insulated wire according to the present invention is an insulated wire formed by forming a first coating layer made of an insulating material on a conductor, forming a second coating layer around the first coating layer, and irradiating with an electron beam,
The thickness of the second coating layer is 1 mm or less, and the adhesion strength between the first coating layer and the second coating layer after the electron beam irradiation is based on the adhesion strength between the first coating layer and the lower layer after the electron beam irradiation. It is small.

  Since the second coating layer is formed on the first coating layer and irradiated with the electron beam, the first coating layer can be irradiated with the electron beam in a state isolated from the atmosphere, that is, oxygen, and the crosslinking of the first coating layer is inhibited. Can be prevented. In addition, the thickness of the second coating layer is 1 mm or less, and the adhesion between the first coating layer and the second coating layer after electron beam irradiation is the adhesion between the first coating layer and the lower layer after electron beam irradiation. Since it is smaller, the second coating layer can be easily removed. Therefore, according to the said insulated wire, the intermediate product from which the insulated wire which improved the surface fusion | melting of the insulated wire in the high temperature environment can be obtained by removing a 2nd coating layer.

In an insulated wire according to the present invention, an insulating layer is formed on a central conductor, an outer conductor is arranged around the insulating layer, a first covering layer made of an insulating material is formed around the outer conductor, and the first An insulated wire formed by forming a second coating layer around the coating layer and irradiating with an electron beam,
The thickness of the second coating layer is 1 mm or less, and the adhesion strength between the first coating layer and the second coating layer after the electron beam irradiation is based on the adhesion strength between the first coating layer and the lower layer after the electron beam irradiation. It is small.
According to the insulated wire, an intermediate product from which an insulated wire with improved surface fusion of the insulated wire in a high temperature environment can be obtained by removing the second coating layer.

The insulated wire according to the present invention is preferably subjected to electron beam irradiation in the atmosphere.
By adopting such a configuration, it is not necessary to specially provide a device for supplying an inert gas to the area where electron beam irradiation is performed, so the device for manufacturing an insulated wire does not become expensive and large. It will end.

  In order to achieve the above-described object, the method for manufacturing an insulated wire according to the present invention includes forming a first coating layer made of an insulating material on a conductor and forming a second coating layer around the first coating layer. The second coating layer is removed after the electron beam irradiation.

According to the method for manufacturing an insulated wire according to the present invention, the second coating layer is formed on the first coating layer, irradiated with the electron beam, and then the second coating layer is removed, whereby the first coating layer is removed from the atmosphere. That is, it is possible to produce an insulated wire that can be irradiated with an electron beam in a state isolated from oxygen and that does not inhibit cross-linking of the first coating layer and does not cause surface fusion even in a high temperature environment.
Also, by using such an insulated wire manufacturing method, it is possible to manufacture an insulated wire even in an air atmosphere, and an apparatus for supplying an inert gas to an area where electron beam irradiation is performed becomes unnecessary. The electric wire manufacturing apparatus is not particularly expensive and large, and an insulated wire can be manufactured at a low cost.

Further, in the manufacturing method according to the present invention, an insulating layer is formed on a central conductor, an outer conductor is arranged around the insulating layer, a first covering layer made of an insulating material is formed around the outer conductor, A second coating layer is formed around the first coating layer, and after the electron beam irradiation, the second coating layer is removed.
According to the manufacturing method of the said structure, even when manufacturing the insulated wire which has an external conductor (shield layer), the insulated wire which does not generate | occur | produce surface fusion in a high temperature environment can be manufactured cheaply.

In the insulated wire manufacturing method according to the present invention, it is preferable that the second covering layer is formed in close contact with the outer peripheral surface of the first covering layer.
By manufacturing in this way, the first coating layer can be reliably isolated from oxygen during electron beam irradiation.

  According to the insulated wire and the insulated wire manufacturing method of the present invention, the second coating layer is formed around the first coating layer, and after the electron beam irradiation, the second coating layer is removed. Wear can be improved. In addition, it is possible to manufacture in an air atmosphere, and it is possible to manufacture an insulated wire at low cost without specially increasing the cost and size of the apparatus.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of an insulated wire according to the present invention. In addition, in this figure, in order to show the structure of a cable clearly, the state which exposed each member which comprises a cable in steps is shown.
FIGS. 2A to 2D are schematic views showing an embodiment of a manufacturing apparatus for manufacturing the insulated wire of the first embodiment, and FIGS. 4A to 4C are insulation of the first embodiment. It is a figure explaining the manufacturing process of an electric wire.

In the insulated wire 10 according to the first embodiment shown in FIG. 1B, the conductor 11 is disposed in the center, and the first covering layer 12 made of an insulating material is formed around the conductor 11.
The conductor 11 is composed of one or a plurality of conductive metal unit wires 13. In the first embodiment, 19 unit wire rods 13 are used, six unit wire rods 13 are twisted around one unit wire rod 13, and the periphery is further twisted by twelve unit wire rods 13. Is used. As shown in FIG. 1A, the unit wire 13 is a bundle of 42 annealed copper wires 13a having a diameter of 0.18 mm, for example, and the diameter thereof is about 1.35 mm.

The 1st coating layer 12 is comprised by thickness 1.1mm, for example, and the outer diameter of an insulated wire is 8.9mm.
As the insulating material constituting the first coating layer 12, an extrudable resin is preferably used, and a polyester resin, a polyolefin resin such as EVA (ethylene vinyl acetate copolymer) or EEA (ethylene ethyl acrylate) is used. Is more preferable, and it is more preferable to use a polyester resin. Use of a polyester resin having excellent heat resistance for the first coating layer 12 is advantageous in securing high heat resistance of the insulated wire 10.
Moreover, the 1st coating layer 12 is irradiated with the electron beam, and it is thought that the insulating material in the 1st coating layer 12 is bridge | crosslinked, and forms the network-like three-dimensional structure. For this reason, the insulated wire 10 is excellent in chemical stability and mechanical strength, and has high heat resistance.

  The insulated wire 10 has a force of 500 gf or less when the two insulated wires 10 are pressed at 0.7 kgf for 1 hour in an atmosphere of 150 ° C. to separate the insulated wires 10. Since the force when separating the insulated wire 10 is as small as 500 gf or less, surface fusion between the insulated wires at high temperatures can be suppressed, and when the insulated wires are separated from each other, abnormalities such as damage to the insulation parts or traces of peeling off are observed. Can be prevented. The insulated wire 10 having such characteristics can be manufactured by a manufacturing method according to this embodiment described below.

  Next, the manufacturing apparatus 20 for suitably manufacturing the insulated wire 10 according to the present embodiment will be described with reference to FIGS. As shown in FIGS. 2A to 2D, the manufacturing apparatus 20 includes a first coating apparatus 21 (FIG. 2A), a second coating apparatus 22 (FIG. 2B), and electron beam irradiation. An apparatus 56 (FIG. 2C) and a peeling apparatus 23 (FIG. 2D) are provided.

The first covering device 21 is a device that manufactures a first material 29 in which the conductor 11 is covered with the first covering layer 12.
As shown in FIG. 2 (A), the first coating device 21 includes a first unwinding portion 26 for feeding the conductor 11, a first extruder 27 for extruding the first coating layer 12, and a first extruder 27. The first cooling device 28 that cools the first coating layer 12 formed in step 1 and the first winding unit 32 that winds up the first material 29 are provided.

The second coating apparatus 22 is an apparatus for manufacturing a second material 37 that is irradiated with an electron beam by further coating the first material 29 manufactured by the first coating apparatus 21 with the second coating layer 14.
As shown in FIG. 2 (B), the second coating device 22 includes a second unwinding part 34 for feeding the first material 29, a second extruder 35 for extruding the second coating layer 14, and a second extrusion. A second cooling device 38 that cools the second coating layer 14 formed by the machine 35 and a second winding unit 42 that winds up the second material 37 are provided.

The electron beam irradiation device 56 is a device that irradiates the second material 37 manufactured by the second coating device 22 with an electron beam.
As shown in FIG. 2C, the electron beam irradiation device 56 includes a third unwinding unit 43 that unwinds the second material 37, an electron beam irradiation unit 36 that irradiates the second material 37 with an electron beam, and an electron beam. And a third winding part 49 for winding the irradiated second material 37.

  The electron beam irradiation unit 36 includes an electron beam irradiation device (not shown) that accelerates electrons by applying a voltage in a vacuum, takes out the accelerated electrons into a normal pressure atmosphere such as air, and emits the electrons. . By irradiating the first coating layer 12 and the second coating layer 14 with an electron beam, the insulating materials constituting the first coating layer 12 and the second coating layer 14 are cross-linked to form a network-like three-dimensional structure. be able to.

The stripping device 23 is a device that removes the second coating layer 14 from the second material 37 manufactured by the second coating device 22.
As shown in FIG. 2D, the stripping apparatus 23 includes a fourth unwinding portion 44 that feeds out the second material 37, a stripped portion 45 that removes the second coating layer 14 from the second material 37, and insulation. And a fourth winding part 47 for winding the electric wire 10.

Here, a schematic view of the peeled portion 45 is shown in FIG. As shown in FIG. 3, the peeled portion 45 includes a pair of split dies 54, and a through hole 54 </ b> A is formed at the center of the pair of split dies 54. Further, the pair of split dies 54 are provided with a pair of blades 55, and the blade tips 55A of the respective blades 55 are arranged so as to protrude into the through holes 54A.
By passing the second material 37 (FIG. 2D) through the through hole 54A, a cutting line is made on the surface of the second coating layer 14 with the cutting edge 55A, and the second coating layer 14 is broken up and down to peel off. can do.

  On the other hand, the device to be peeled 23 (FIG. 2D) includes a fifth winding unit 52. The fifth winding unit 52 includes a pair of feed rollers 48 that guide the removed second coating layer 14 and a second coating layer winding roll 51 that winds the second coating layer 14.

Next, a method of manufacturing the insulated wire 10 using the insulated wire manufacturing apparatus 20 will be described based on FIGS. 2 (A) to (D) and FIGS. 4 (A) to (C).
First, a plurality of annealed copper wires drawn to a predetermined diameter are twisted together to form a conductor 11 and wound around an unwinding roll 25 (FIG. 2A).
A first coating layer 12 made of, for example, a polyester resin is extrusion-coated around the conductor 11 using the first coating device 21 shown in FIG. Specifically, the unwinding roll 25 on which the conductor 11 is wound is set on the first unwinding portion 26, and the unwinding roll 25 is rotated in the direction of arrow A to unwind the conductor 11. By passing the drawn-out conductor 11 through the first extruder 27, the first coating layer 12 is extrusion-coated around the conductor 11.

Then, the first coating layer 12 is cooled by the first cooling device 28, and the first material 29 is wound around the first winding / unwinding roll 31.
The first material 29 manufactured in this manner is obtained by covering the conductor 11 with the first coating layer 12 as shown in FIG. In this state, the first coating layer 12 is only cooled and dried, and the resin is not crosslinked.

Next, the second coating layer 14 is extrusion coated on the first coating layer 12 using the second coating device 22 shown in FIG.
Specifically, the first winding / unwinding roll 31 on which the first material 29 is wound is set on the second unwinding section 34, and the first winding / unwinding roll 31 is rotated in the direction of arrow A. Then, one material 29 is fed out. By passing the fed first material 29 through the second extruder 35, the second coating layer 14 is extrusion coated.

Then, the second coating layer is cooled by the second cooling device 38, and the second material 37 is wound around the second winding / unwinding roll 41.
The second material 37 is irradiated with an electron beam by using an electron beam irradiation apparatus 56 shown in FIG. Specifically, the second winding / unwinding roll 41 on which the second material 37 is wound is set on the third unwinding portion 43, and the second winding / unwinding roll 41 is rotated in the direction of arrow A. Then, the second material 37 is fed out and conveyed to the electron beam irradiation unit 36. The electron beam irradiation unit 36 irradiates the second material 37 with an electron beam, crosslinks the whole of these coating layers, and cures them. Then, the second material 37 irradiated with the electron beam is wound around the third winding / unwinding roll 57.

  As shown in FIG. 4B, the second material 37 manufactured in this manner is formed with the second coating layer 14 in close contact with the outer peripheral surface 12A of the first coating layer 12. Accordingly, the first coating layer 12 is crosslinked by being irradiated with an electron beam in a state isolated from the atmosphere, that is, oxygen. The second material 37 is used as an intermediate product that can easily obtain an insulated wire with improved surface fusion of the insulated wire in a high temperature environment by removing the second coating layer 14 as will be described later. be able to.

Here, it is desirable that the second coating layer 14 has a thickness of 0.2 mm or more. By setting the thickness of the second coating layer 14 to 0.2 mm or more, the first coating layer 12 can be irradiated with an electron beam in a state where oxygen is completely blocked, and the thickness of the second coating layer 14 is uneven when the second coating layer 14 is formed. However, since it can prevent that the 1st coating layer 12 is exposed to the surface, the bridge | crosslinking inhibition by oxygen can be suppressed reliably.
Moreover, it is preferable that the thickness of the 2nd coating layer 14 is 1 mm or less, and it is more preferable that it is 0.5 mm or less. By setting the thickness of the second coating layer 14 to 1 mm or less, the second coating layer 14 can be easily removed from the first coating layer 12 in the step of removing the second coating layer 14 described later.

The second covering layer 14 is preferably formed from an insulating material. By forming the second coating layer 14 from an insulating material such as a resin, it is possible to form the second coating layer by an inexpensive and easy means such as extrusion molding. In the removal, the insulating material that can be removed by means such as breaking can be made of polyethylene resin, PVC resin, EVA resin, ionomer, or the like.

Moreover, it is preferable that the thermal deformation temperature of the insulating material constituting the second coating layer 14 is lower than the thermal deformation temperature of the insulating material constituting the first coating layer 12.
Thus, by making the thermal deformation temperature of the second coating layer 14 lower than the thermal deformation temperature of the first coating layer 12, when the second coating layer 14 is extrusion coated around the first coating layer 12, Since the first coating layer 12 does not melt, the adhesion between the first coating layer 12 and the second coating layer 14 can be reduced, and the removal of the second coating layer 14 can be facilitated.

Furthermore, the adhesion force between the first coating layer 12 and the second coating layer 14 after the electron beam irradiation is set to be smaller than the adhesion force between the first coating layer 12 after the electron beam irradiation and the conductor 11 as a lower layer. Preferably it is.
The second coating layer 14 is removed from the first coating layer 12 by setting the adhesion between the first coating layer 12 and the second coating layer 14 to be smaller than the adhesion between the conductor 11 and the first coating layer 12. At this time, since there is no possibility of lowering the adhesion between the conductor 11 and the first covering layer 12, it is possible to prevent the dielectric constant of the insulated wire 10 from being lowered. In addition, when the insulated wire 10 is laid or further processed, the first coating layer 12 is not detached from the conductor 11, and there is no possibility of affecting the workability and workability of the insulated wire 10.
In addition, the adhesion strength between the first coating layer 12 and the second coating layer 14 and the adhesion strength between the conductor 11 and the first coating layer 12 are the types of materials constituting the first coating layer 12 and the second coating layer 14. , And can be adjusted as appropriate depending on the additive.

Finally, the second coating layer 14 is removed using the peeling apparatus 23 shown in FIG.
Specifically, the third winding / unwinding roll 57 around which the second material 37 is wound is set on the fourth unwinding portion 44, and the third winding / unwinding roll 57 is rotated in the direction of arrow A. Then, the second material 37 is fed out. The fed second material 37 is conveyed to the peeled portion 45, and the second coating layer 14 is peeled and removed by passing the through hole 54A (FIG. 3) through the peeled portion 45.

By removing the second coating layer 14, the insulated wire 10 shown in FIG. 4C is obtained, and finally the insulated wire 10 is wound around the product winding roll 46.
On the other hand, the peeled second coating layer 14 is collectively wound around the second coating layer winding roll 51. Thereby, the process of manufacturing the insulated wire 10 is completed.

  As described above, according to the insulated wire 10 of the first embodiment, the second coating layer 14 is extrusion-coated on the first coating layer 12, and after the electron beam irradiation, the second coating layer 14 is removed. By doing so, the first coating layer 12 can be irradiated with an electron beam while being isolated from the atmosphere, that is, from oxygen. Therefore, the insulated wire 10 does not inhibit cross-linking of the first coating layer 12 and does not cause surface fusion between the insulated wires even when placed in a high-temperature environment, so that good quality can be maintained. .

  Furthermore, according to the manufacturing method according to the first embodiment, since the first coating layer 12 is covered with the second coating layer 14, the first coating layer 12 can be isolated from the atmosphere, that is, oxygen. A special device for supplying the inert gas is not necessary. Therefore, the manufacturing apparatus 20 for the insulated wire 10 does not need to be particularly expensive and large.

  In the manufacturing process of the insulated wire 10 according to the first embodiment, the first covering layer 12 and the second covering layer 14 are formed on separate manufacturing lines. However, the present invention is not necessarily limited to this. The second coating device 22 may be arranged downstream of the first coating device 21 and the first coating layer 12 and the second coating layer 14 may be formed on the same production line. .

  Moreover, the manufacturing method of the insulated wire which concerns on this invention may perform not the formation of the 1st coating layer 12 and the 2nd coating layer 14 with a separate extruder but a single extruder. That is, you may form by carrying out the extrusion coating of the 1st coating layer 12 and the 2nd coating layer 14 simultaneously using the extruder which can carry out the extrusion coating of the two resin layers simultaneously. When the first coating layer 12 and the second coating layer 14 are simultaneously formed in this way, the first coating layer 12 and the second coating layer 14 are not formed in separate steps, so that productivity is improved and cost reduction is achieved. Can be planned.

In the insulated wire according to the present invention, it is possible to provide a groove along the longitudinal direction on the surface of the second covering layer 14 of the second material 37 shown in FIG. For example, as shown in FIGS. 5A and 5B, a pair of grooves 61 can be provided on the surface 14A of the second coating layer 14 at intervals of 180 ° along the longitudinal direction.
Thus, by providing the groove 61 along the longitudinal direction on the surface of the second coating layer 14, the second coating layer 14 can be easily broken from the groove 61 without using the blade 55 shown in FIG. It becomes possible to divide | segment, and the 2nd coating layer 14 can be removed easily.

  Next, 2nd Embodiment which concerns on the insulated wire of this invention is described based on FIG. In the second embodiment, the same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In the insulated wire 70 according to the second embodiment shown in FIG. 6, a central conductor 74 is disposed in the center, and an insulating layer 71 is formed around the central conductor 74. An outer conductor 72 is provided around the insulating layer 71, and the first coating layer 12 is formed around the outer conductor 72.
The central conductor 74 is formed by twisting six unit wire rods 13 around one unit wire rod 13 using, for example, seven conductive metal unit wire rods 13.

For the insulating layer 71, for example, a resin such as polyethylene or polyvinyl chloride is used, and an electron beam cross-linked heat-resistant plastic can be preferably used.
The outer conductor 72 is formed so as to cover the periphery of the insulating layer 71 by braiding or laterally winding a plurality of thin conductive metal wires (for example, annealed copper wire). The outer conductor 72 of this embodiment is a braided annealed copper wire.

As in the first embodiment, the insulated wire 70 of the second embodiment is formed by extruding the second coating layer 14 in close contact with the first coating layer 12 and irradiating it with an electron beam. Manufactured by stripping layer 14.
By manufacturing in this way, also in the insulated wire 70 which concerns on 2nd Embodiment, the effect similar to 1st Embodiment can be acquired.

  Also in the second embodiment, the adhesion between the first coating layer 12 and the second coating layer 14 after the electron beam irradiation is the adhesion between the first coating layer 12 after the electron beam irradiation and the external conductor 72 which is the lower layer. It is preferable to be smaller than the force. By setting the adhesion force in this way, only the second coating layer 14 can be easily removed, and the adhesion between the first coating layer 12 and the external conductor 74 when the second coating layer 14 is removed. The influence on workability and dielectric constant due to the decrease can be avoided.

  Similarly to the second material 37 of the first embodiment, in the process of manufacturing the insulated wire 70, an insulated wire (not shown) including the second coating layer 14 is formed around the first coating layer 12. . This insulated wire can also be used as an intermediate product that can easily obtain an insulated wire with improved surface fusion of the insulated wire in a high temperature environment by removing the second coating layer 14.

  In addition, the material, shape, dimension, form, number, and arrangement of the conductor 11, the central conductor 74, the first covering layer 12, the second covering layer 14, the groove 61, the insulated wire manufacturing apparatus 20 and the like exemplified in the above-described embodiment. The location is arbitrary as long as the present invention can be achieved, and is not limited.

The insulated wire 10 according to the first embodiment described above is taken as Example 1, and the insulated wire 70 according to the second embodiment is taken as Example 2. Moreover, an Example and a comparative example were evaluated by making the insulated wire manufactured in the atmosphere of the inert gas demonstrated by the prior art into a comparative example.
In the evaluation method, first, the insulated wires of the sample were brought into contact with each other with a constant load (0.7 kgf), and left in a constant temperature bath at 150 ° C. for 1 hour. After taking out from the thermostat and air-cooling, the insulated wires were separated from each other with a tensile tester, and the peeling force at this time was measured. Moreover, the presence or absence of the peeling trace on the surface of an insulated wire was observed. The results are shown in Table 1.

When the insulated wires 10 and 70 were pulled away from the first coating layer 12, no peeling marks were observed on the surface of the first coating layer 12.
That is, according to the insulated wires 10 and 70 of the first and second embodiments, surface fusion between the insulated wires 12 can be prevented by performing electron beam irradiation in a state where the first covering layer 12 is isolated from oxygen. I understand that.
The peeling force when separating the second coating layer 14 from the first coating layer 12 of the insulated wire 10 was 10 gf. About the insulated wire 70, it was 25 gf.

On the other hand, in the insulated wire of the comparative example, when the second coating layer was separated from the first coating layer, a whitish strip-like peeling trace was observed on the surface of the first coating layer.
In the case of the comparative example, the peeling force when separating the second coating layer from the first coating layer was 550 gf.

It is a perspective view showing a 1st embodiment of an insulated wire concerning the present invention. (A)-(D) are schematic which shows the manufacturing apparatus of the insulated wire of 1st Embodiment. It is the schematic of the to-be-stripped part 45 shown to FIG. 2 (D). (A)-(C) are the figures explaining the manufacturing process of the insulated wire of 1st Embodiment. (A) is sectional drawing which shows 2nd Embodiment of the insulated wire which concerns on this invention, (B) is a perspective view which shows 2nd Embodiment of the insulated wire which concerns on this invention. It is a perspective view which shows 3rd Embodiment of the insulated wire which concerns on this invention.

Explanation of symbols

10, 70 Insulated wire 11, 74 Conductor 12 First covering layer 14 Second covering layer 37 Second material (insulated wire)
61 Groove 71 Insulating layer 72 Outer conductor 74 Center conductor

Claims (15)

A first coating layer made of an insulating material is formed on a conductor, a second coating layer is formed around the first coating layer, and after the electron beam irradiation, the second coating layer is removed. Insulated wire. An insulating layer is formed on the central conductor, an outer conductor is arranged around the insulating layer, a first covering layer made of an insulating material is formed around the outer conductor, and a second covering is formed around the first covering layer. After forming a layer and irradiating with an electron beam, the said 2nd coating layer was removed, The insulated wire characterized by the above-mentioned. The insulated wire according to claim 1 or 2, wherein the second covering layer is made of an insulating material. The insulated wire according to claim 3, wherein the heat deformation temperature of the insulating material of the second covering layer is lower than the heat deformation temperature of the insulating material of the first covering layer. The thickness of the said 2nd coating layer is 1 mm or less, The insulated wire of any one of Claims 1-4 characterized by the above-mentioned. The insulated wire according to any one of claims 1 to 5, wherein a groove is provided along a longitudinal direction on a surface of the second covering layer. The adhesion strength between the first coating layer after electron beam irradiation and the second coating layer is smaller than the adhesion strength between the first coating layer after electron beam irradiation and its lower layer. The insulated wire of Claim 1. The insulated wire according to any one of claims 1 to 7, wherein the insulating material constituting the first covering layer is a polyester resin. The two insulated wires are pressed at 0.7 kgf for 1 hour in an atmosphere of 150 ° C., and the force when separating the insulated wires from each other is 500 gf or less. The insulated wire as described in the item. Forming a first coating layer made of an insulating material on a conductor, forming a second coating layer around the first coating layer, and an insulated electric wire irradiated with an electron beam,
The thickness of the second coating layer is 1 mm or less, and the adhesion strength between the first coating layer and the second coating layer after the electron beam irradiation is based on the adhesion strength between the first coating layer and the lower layer after the electron beam irradiation. An insulated wire characterized by being small. An insulating layer is formed on the central conductor, an outer conductor is arranged around the insulating layer, a first covering layer made of an insulating material is formed around the outer conductor, and a second covering is formed around the first covering layer. An insulated wire formed with a layer and irradiated with an electron beam,
The thickness of the second coating layer is 1 mm or less, and the adhesion strength between the first coating layer and the second coating layer after the electron beam irradiation is based on the adhesion strength between the first coating layer and the lower layer after the electron beam irradiation. An insulated wire characterized by being small. The insulated wire according to any one of claims 1 to 11, wherein the electron beam irradiation is performed in the atmosphere. A first coating layer made of an insulating material is formed on a conductor, a second coating layer is formed around the first coating layer, and after the electron beam irradiation, the second coating layer is removed. Insulated wire manufacturing method. An insulating layer is formed on the central conductor, an outer conductor is arranged around the insulating layer, a first covering layer made of an insulating material is formed around the outer conductor, and a second covering is formed around the first covering layer. After forming a layer and irradiating with an electron beam, the said 2nd coating layer is removed, The manufacturing method of the insulated wire characterized by the above-mentioned. The method for manufacturing an insulated wire according to claim 13 or 14, wherein the second coating layer is formed in close contact with an outer peripheral surface of the first coating layer.

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